2 files changed, 25 insertions, 10 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 4c9c5092bd5..af5025f7a82 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+1999-10-15  Gerd Moellmann  <gerd@gnu.org>
+
+        * xfns.c (gif_load): Fix handling of interlaced GIFs.
+
 1999-10-14  Dave Love  <fx@gnu.org>
 
         * xdisp.c (handle_fontified_prop): GCPRO `pos'.
diff --git a/src/xfns.c b/src/xfns.c
index 4afa9d2dee8..eee9b919eef 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -7966,7 +7966,7 @@ static struct image_keyword png_format[PNG_LAST] =
   {":heuristic-mask",   IMAGE_DONT_CHECK_VALUE_TYPE,            0}
 };
 
-/* Structure describing the image type `gif'.  */
+/* Structure describing the image type `png'.  */
 
 static struct image_type png_type =
 {
@@ -8958,17 +8958,28 @@ gif_load (f, img)
       static int interlace_start[] = {0, 4, 2, 1};
       static int interlace_increment[] = {8, 8, 4, 2};
       int pass, inc;
+      int row = interlace_start[0];
+
+      pass = 0;
 
-      for (pass = 0; pass < 4; ++pass)
+      for (y = 0; y < image_height; y++)
         {
-          inc = interlace_increment[pass];
-          for (y = interlace_start[pass]; y < image_height; y += inc)
-            for (x = 0; x < image_width; ++x)
-              {
-                unsigned i = gif->SavedImages[ino].RasterBits[y * image_width + x];
-                XPutPixel (ximg, x + image_left, y + image_top, 
-                           pixel_colors[i]);
-              }
+          if (row >= image_height)
+            {
+              row = interlace_start[++pass];
+              while (row >= image_height)
+                row = interlace_start[++pass];
+            }
+          
+          for (x = 0; x < image_width; x++)
+            {
+              unsigned int i
+                = gif->SavedImages[ino].RasterBits[(y * image_width) + x];
+              XPutPixel (ximg, x + image_left, row + image_top,
+                         pixel_colors[i]);
+            }
+          
+          row += interlace_increment[pass];
         }
     }
   else